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1.
Nutr Neurosci ; 27(4): 300-309, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36932327

RESUMO

Nutrition is a modifiable risk factor for ischemic stroke. As people age their ability to absorb some nutrients decreases, a primary example is vitamin B12. Older individuals with a vitamin B12 deficiency are at a higher risk for ischemic stroke and have worse stroke outcome. However, the mechanisms through which these occur remain unknown. The aim of the study was to investigate the role of vitamin B12 deficiency in ischemic stroke outcome and mechanistic changes in a mouse model. Ten-month-old male and female mice were put on control or vitamin B12 deficient diets for 4 weeks prior to and after ischemic stroke to the sensorimotor cortex. Motor function was measured, and tissues were collected to assess potential mechanisms. All deficient mice had increased levels of total homocysteine in plasma and liver tissues. After ischemic stroke, deficient mice had impaired motor function compared to control mice. There was no difference between groups in ischemic damage volume. However, within the ischemic damage region, there was an increase in total apoptosis of male deficient mice compared to controls. Furthermore, there was an increase in neuronal survival in ischemic brain tissue of the vitamin B12 deficient mice compared to controls. Additionally, there were changes in choline metabolites in ischemic brain tissue because of a vitamin B12 deficiency. The data presented in this study confirms that a vitamin B12 deficiency worsens stroke outcome in male and female mice. The mechanisms driving this change may be a result of neuronal survival and compensation in choline metabolism within the damaged brain tissue.


Assuntos
AVC Isquêmico , Acidente Vascular Cerebral , Deficiência de Vitamina B 12 , Humanos , Pessoa de Meia-Idade , Masculino , Animais , Feminino , Camundongos , Lactente , Ácido Fólico , Dieta , Deficiência de Vitamina B 12/complicações , Deficiência de Vitamina B 12/metabolismo , Acidente Vascular Cerebral/complicações , Vitamina B 12 , Colina , Homocisteína
2.
Am J Physiol Heart Circ Physiol ; 325(6): H1354-H1359, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-37801048

RESUMO

Adequate maternal dietary levels of one-carbon metabolites, such as folic acid and choline, play an important role in the closure of the neural tube in utero; however, the impact of deficiencies in one-carbon (1C) metabolism on offspring neurological function after birth remain undefined. Stroke is one of the leading causes of death and disability globally. The aim of our study was to determine the impact of maternal 1C nutritional deficiencies on cerebral and peripheral blood flow after ischemic stroke in adult female offspring. In this study, female mice were placed on either control (CD)-, folic acid (FADD)-, or choline (ChDD)-deficient diets before pregnancy. Female offspring were weaned onto a CD for the duration of the study. Ischemic stroke was induced in offspring and after 6 wk cerebral and peripheral blood flow velocity was measured using ultrasound imaging. Our data showed that 11.5-mo-old female offspring from ChDD mothers had reduced blood flow in the posterior cerebral artery compared with controls. In peripheral blood flow velocity measurements, we report an aging effect. These results emphasize the importance of maternal 1C diet in early life neuro-programming on long-term vasculature health.NEW & NOTEWORTHY We demonstrate that a maternal dietary deficiency in one-carbon (1C) metabolites result in reduced cerebral blood flow in adult female offspring after ischemic stroke, but the long-term effects are not present. This result points to the key role of the maternal diet in early life neuroprogramming, while emphasizing its effects on both fetal development and long-term cerebrovascular health.


Assuntos
AVC Isquêmico , Efeitos Tardios da Exposição Pré-Natal , Gravidez , Camundongos , Feminino , Animais , Humanos , Ácido Fólico/metabolismo , Dieta , Colina , Carbono , Fenômenos Fisiológicos da Nutrição Materna
3.
Nutr Neurosci ; 25(3): 558-566, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32448097

RESUMO

Objective: Elevated homocysteine concentrations are a risk factor for stroke. A common genetic polymorphism in methylenetetrahydrofolate reductase (MTHFR 677 C→T) results in elevated levels of homocysteine. MTHFR plays a critical role in the synthesis of S-adenosylmethionine (SAM), a global methyl donor. Our previous work has demonstrated that Mthfr+/- mice, which model the MTHFR polymorphism in humans, are more vulnerable to ischemic damage. The aim of this study was to investigate the cellular mechanisms by which the MTHFR-deficiency changes the brain in the context of ischemic stroke injury.Methods: In the present study, three-month-old male Mthfr+/- and wild-type littermate mice were subjected to photothrombosis (PT) damage. Four weeks after PT damage, animals were tested on behavioral tasks, in vivo imaging was performed using T2-weighted MRI, and brain tissue was collected for histological analysis.Results: Mthfr+/- animals used their non-impaired forepaw more to explore the cylinder and had a larger damage volume compared to wild-type littermates. In brain tissue of Mthfr+/- mice methionine adenosyltransferase II alpha (MAT2A) protein levels were decreased within the damage hemisphere and increased levels in hypoxia-induced factor 1 alpha (HIF-1α) in non-damage hemisphere. There was an increased antioxidant response in the damage site as indicated by higher levels of nuclear factor erythroid 2-related factor 2 (Nrf2) in neurons and astrocytes and neuronal superoxide dismutase 2 (SOD2) levels.Conclusions: Our results suggest that Mthfr+/- mice are more vulnerable to PT-induced stroke damage through the regulation of the cellular response. The increased antioxidant response we observed may be compensatory to the damage amount.


Assuntos
Homocistinúria , AVC Isquêmico , Metilenotetra-Hidrofolato Redutase (NADPH2) , Espasticidade Muscular , Animais , Homocisteína , Homocistinúria/complicações , AVC Isquêmico/genética , AVC Isquêmico/patologia , Masculino , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Camundongos , Transtornos Psicóticos
4.
Nutr Neurosci ; 25(10): 2057-2065, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34042561

RESUMO

OBJECTIVE: One-carbon (1C) metabolism is a metabolic network that integrates nutritional signals with biosynthesis, redox homeostasis, and epigenetics. There are sex differences in hepatic 1C metabolism, however, it is unclear whether sex differences in 1C impact the brain. The aim of this study was to investigate if sex modulates the effects of dietary folic acid deficiency, the main component of 1C, in brain tissue using a mouse model. METHODS: Male and female C57Bl/6J mice were placed on a folic acid deficient (FD) or control diet (CD) at six weeks until six months of aged. After which brain tissue and serum were collected for analysis. In brain tissue, hippocampal volume, morphology, and apoptosis as well as cortical acetylcholine metabolism were measured. RESULTS: Male and female FD mice had reduced serum levels of folate. Both males and females maintained on a FD showed a decrease in the thickness of the hippocampal CA1-CA3 region. Interestingly, there was a sex difference in the levels of active caspase-3 within the CA3 region of the hippocampus. In cortical tissue, there were increased levels of neuronal ChAT and reduced levels of AChE in FD females and male mice. CONCLUSIONS: The results indicated that FD impacts hippocampal morphology and cortical neuronal acetylcholine metabolism. The data from our study indicate that there was only one sex difference and that was in hippocampal apoptosis. Our study provides little evidence that sex modulates the effects of dietary folate deficiency on hippocampal morphology and cortical neuronal acetylcholine metabolism.


Assuntos
Deficiência de Ácido Fólico , Acetilcolina/metabolismo , Carbono , Caspase 3/metabolismo , Dieta , Feminino , Ácido Fólico , Hipocampo/metabolismo , Humanos , Masculino
5.
J Neurosci Res ; 99(1): 284-293, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32112450

RESUMO

In offspring, an adequate maternal diet is important for neurodevelopment. One mechanism by which maternal diet impacts neurodevelopment is through its dynamic role in the development of the gut microbiota. Communication between the gut, and its associated microbiota, and the brain is facilitated by the vagus nerve, in addition to other routes. Currently, the mechanisms through which maternal diet impacts offspring microbiota development are not well-defined. Therefore, this review aims to investigate the relationship between maternal diet during pregnancy and offspring microbiota development and its impact on neurodevelopment. Both human and animal model studies were reviewed to understand the impact of maternal diet on offspring microbiota development and potential consequences on neurodevelopment. In the period after birth, as reported in both human and model system studies, maternal diet impacts offspring bacterial colonization (e.g., decreased presence of Lactobacillus reuteri as a result of a high-fat maternal diet). It remains unknown whether these changes persist into adulthood and whether they impact vulnerability to disease. Therefore, further long-term studies are required in both human and model systems to study these changes. Our survey of the literature indicates that maternal diet influences early postnatal microbiota development, which in turn, may serve as a mechanism through which maternal diet impacts neurodevelopment.


Assuntos
Microbioma Gastrointestinal , Fenômenos Fisiológicos da Nutrição Pré-Natal , Animais , Feminino , Humanos , Gravidez , Efeitos Tardios da Exposição Pré-Natal
6.
Curr Opin Clin Nutr Metab Care ; 24(4): 303-307, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33631772

RESUMO

PURPOSE OF REVIEW: Ischemic stroke results in disability and mortality worldwide. Nutrition is a modifiable risk factor for stroke. For example, deficiencies in one-carbon metabolism have been linked to increased risk of stroke through elevated levels of homocysteine. Some countries world-wide fortify their diets with folates to prevent neural tube defects, but deficiencies in other one-carbon metabolites, such as vitamin B12 and choline are still present in many populations. The aim of this review is to understand the current evidence on how dietary supplementation by nutrients which modulate one-carbon metabolism impact stroke outcome. RECENT FINDINGS: The results from clinical studies evaluating lowering homocysteine through B-vitamin supplementation on stroke risk remain unclear. Other clinical and preclinical studies have shown increasing dietary intake of one-carbon metabolism has some benefit on stroke outcome. Preclinical studies have shown that increased levels of nutrients which modulate one-carbon metabolism help facilitate recovery in damage models of the central nervous system. One the mechanisms driving these changes is neuroplasticity. SUMMARY: The data suggest that increasing dietary nutrients that modulate one-carbon metabolites in patients that are at a higher risk for and suffer from central nervous system diseases, such as stroke, could benefit in addition to other therapies.


Assuntos
Acidente Vascular Cerebral , Complexo Vitamínico B , Carbono , Suplementos Nutricionais , Ácido Fólico , Humanos , Acidente Vascular Cerebral/prevenção & controle
7.
Neurobiol Dis ; 132: 104613, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31525435

RESUMO

The prevalence of stroke increases with age and the ability to absorb all nutrients from our diets decreases with age. Nutrition is a modifiable risk factor for stroke, which is a leading cause of death and disability in world-wide. Deficiencies in one­carbon metabolism, including in methyltetrahydrofolate reductase (MTHFR), have been linked to increased risk of stroke. The Mthfr+/- mice mouse model mimic the phenotype of the MTHFR677C➔T polymorphism, such as elevated levels of homocystine. Using this mouse model, the aim of this study was to investigate the impact of dietary supplementation with 5-methylTHF, vitamin B12, and choline after ischemic stroke. Male Mthfr+/- and wildtype littermate control mice were aged (~1.5-year-old) and were placed on control diet (CD) 4-weeks prior to sensorimotor cortex damage using photothrombosis (PT), a model for ischemic stroke. Post-operatively, one group of Mthfr+/- and wildtype littermate mice were placed on 5-methylTHF, vitamin B12, and choline supplemented diet (SD). Four weeks after PT and SD motor function was assessed using the accelerating rotarod, forepaw asymmetry, and ladder beam walking tasks. Total homocysteine and cysteine levels were measured in blood. Brain tissue was processed to assess lesion volume and investigate biochemical and molecular changes. After PT and SD, Mthfr+/- mice were able to stay on the accelerating rotarod longer and used their impaired forepaw to explore more when compared to CD animals. Furthermore, total homocysteine levels in plasma and lesion volume were reduced in Mthfr+/+ and Mthfr+/- SD mice. Within the damage site, there were reduced levels of apoptotic cell death and increased neuroprotective cellular response in the brains of SD treated Mthfr+/- mice. This study reveals a critical role for one­carbon supplementation, with 5-methylTHF, vitamin B12, and choline, in supporting improvement after ischemic stroke damage.


Assuntos
Colina/farmacologia , Suplementos Nutricionais , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Acidente Vascular Cerebral/fisiopatologia , Tetra-Hidrofolatos/farmacologia , Vitamina B 12/farmacologia , Envelhecimento , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Encéfalo/fisiopatologia , Masculino , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Camundongos , Camundongos Endogâmicos C57BL , Recuperação de Função Fisiológica/efeitos dos fármacos
8.
Hum Mol Genet ; 26(5): 888-900, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28069796

RESUMO

Methylenetetrahydrofolate reductase (MTHFR) generates methyltetrahydrofolate for methylation reactions. Severe MTHFR deficiency results in homocystinuria and neurologic impairment. Mild MTHFR deficiency (677C > T polymorphism) increases risk for complex traits, including neuropsychiatric disorders. Although low dietary folate impacts brain development, recent concerns have focused on high folate intake following food fortification and increased vitamin use. Our goal was to determine whether high dietary folate during pregnancy affects brain development in murine offspring. Female mice were placed on control diet (CD) or folic acid-supplemented diet (FASD) throughout mating, pregnancy and lactation. Three-week-old male pups were evaluated for motor and cognitive function. Tissues from E17.5 embryos, pups and dams were collected for choline/methyl metabolite measurements, immunoblotting or gene expression of relevant enzymes. Brains were examined for morphology of hippocampus and cortex. Pups of FASD mothers displayed short-term memory impairment, decreased hippocampal size and decreased thickness of the dentate gyrus. MTHFR protein levels were reduced in FASD pup livers, with lower concentrations of phosphocholine and glycerophosphocholine in liver and hippocampus, respectively. FASD pup brains showed evidence of altered acetylcholine availability and Dnmt3a mRNA was reduced in cortex and hippocampus. E17.5 embryos and placentas from FASD dams were smaller. MTHFR protein and mRNA were reduced in embryonic liver, with lower concentrations of choline, betaine and phosphocholine. Embryonic brain displayed altered development of cortical layers. In summary, high folate intake during pregnancy leads to pseudo-MTHFR deficiency, disturbed choline/methyl metabolism, embryonic growth delay and memory impairment in offspring. These findings highlight the unintended negative consequences of supplemental folic acid.


Assuntos
Ácido Fólico/efeitos adversos , Homocistinúria/genética , Memória de Curto Prazo/efeitos dos fármacos , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Espasticidade Muscular/genética , Acetilcolina/genética , Acetilcolina/metabolismo , Animais , DNA (Citosina-5-)-Metiltransferases/genética , DNA (Citosina-5-)-Metiltransferases/metabolismo , DNA Metiltransferase 3A , Dieta/efeitos adversos , Feminino , Ácido Fólico/administração & dosagem , Homocistinúria/induzido quimicamente , Homocistinúria/patologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Transtornos da Memória/induzido quimicamente , Transtornos da Memória/fisiopatologia , Metilação , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Camundongos , Espasticidade Muscular/induzido quimicamente , Espasticidade Muscular/patologia , Gravidez , Transtornos Psicóticos/genética , Transtornos Psicóticos/patologia
9.
Expert Rev Proteomics ; 16(9): 727-731, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31422714

RESUMO

Introduction: Preterm birth is a major global health concern, contributing to 35% of all neonatal deaths in 2016. Given the importance of accurately ascertaining estimates of preterm birth and in light of current limitations in postnatal gestational age (GA) estimation, novel methods of estimating GA postnatally in the absence of prenatal ultrasound are needed. Previous work has demonstrated the potential for metabolomics to estimate GA by analyzing data captured through routine newborn screening. Areas covered: Circulating analytes found in newborn blood samples vary by GA. Leveraging newborn screening and demographic data, our group developed an algorithm capable of estimating GA postnatally to within approximately 1 week of ultrasound-validated GA. Since then, we have built on the model by including additional analytes and validating the model's performance through internal and external validation studies, and through implementation of the model internationally. Expert opinion: Currently, using metabolomics to estimate GA postnatally holds considerable promise but is limited by issues of cost-effectiveness and resource access in low-income settings. Future work will focus on enhancing the precision of this approach while prioritizing point-of-care testing that is both accessible and acceptable to individuals in low-resource settings.


Assuntos
Proteínas Sanguíneas/genética , Idade Gestacional , Metabolômica/tendências , Triagem Neonatal/tendências , Algoritmos , Feminino , Humanos , Recém-Nascido , Cuidado Pós-Natal/métodos , Gravidez
10.
Nutr Res Rev ; 32(2): 218-230, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31303188

RESUMO

Parkinson's disease (PD) is the second most common neurodegenerative disorder. It is characterised by the progressive degeneration of dopaminergic (DA) neurons. The cause of degeneration is not well understood; however, both genetics and environmental factors, such as nutrition, have been implicated in the disease process. Deficiencies in one-carbon metabolism in particular have been associated with increased risk for PD onset and progression, though the precise relationship is unclear. The aim of the present review is to determine the role of one-carbon metabolism and elevated levels of homocysteine in PD onset and pathology and to identify potential mechanisms involved. A search of PubMed, Google Scholar and Web of Science was undertaken to identify relevant human and animal studies. Case-control, prospective cohort studies, meta-analyses and non-randomised trials were included in the present review. The results from human studies indicate that polymorphisms in one-carbon metabolism may increase risk for PD development. There is an unclear role for dietary B-vitamin intake on PD onset and progression. However, dietary supplementation with B-vitamins may be beneficial for PD-affected individuals, particularly those on l-DOPA (levodopa or l-3,4-dihydroxyphenylalanine) treatment. Additionally, one-carbon metabolism generates methyl groups, and methylation capacity in PD-affected individuals is reduced. This reduced capacity has an impact on expression of disease-specific genes that may be involved in PD progression. During B-vitamin deficiency, animal studies report increased vulnerability of DA cells through increased oxidative stress and altered methylation. Nutrition, especially folates and related B-vitamins, may contribute to the onset and progression of PD by making the brain more vulnerable to damage; however, further investigation is required.


Assuntos
Homocisteína/metabolismo , Transferases de Grupo de Um Carbono/genética , Transferases de Grupo de Um Carbono/metabolismo , Doença de Parkinson/etiologia , Animais , Dieta , Ácido Fólico/metabolismo , Predisposição Genética para Doença , Humanos , Levodopa/uso terapêutico , Metilação , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Estado Nutricional , Doença de Parkinson/genética , Doença de Parkinson/terapia , Polimorfismo Genético , Complexo Vitamínico B/administração & dosagem
11.
Neurobiol Dis ; 103: 89-100, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28396257

RESUMO

Folates are B-vitamins that play an important role in brain function. Dietary and genetic deficiencies in folate metabolism result in elevated levels of homocysteine which have been linked to increased risk of developing a stroke. Reducing levels of homocysteine before or after a stroke through B-vitamin supplementation has been a focus of many clinical studies, however, the results remain inconsistent. Animal model systems provide a powerful mechanism to study and understand functional impact and mechanisms through which supplementation affects stroke recovery. The aim of this study was to understand the role of B-vitamins in stroke pathology using in vivo and in vitro mouse models. The first objective assessed the impact of folate deficiency prior to ischemic damage followed by B-vitamins and choline supplementation. Ischemic damage targeted the sensorimotor cortex. C57Bl/6 wild-type mice were maintained on a folic acid deficient diet for 4weeks prior to ischemic damage to increased levels of plasma homocysteine, a risk factor for stroke. Post-operatively mice were placed on a B-vitamin and choline supplemented diet for a period of four weeks, after which motor function was assessed in mice using the rotarod, ladder beam and forepaw asymmetry tasks. The second objective was to determine how a genetic deficiency in methylenetetrahydrofolate reductase (MTHFR), an enzyme involved in folate metabolism, increases vulnerability to stroke. Primary cortical neurons were isolated from Mthfr+/+, Mthfr+/- and Mthfr-/- embryos and were exposed to in vitro models of stroke which include hypoxia or oxygen glucose deprivation. Cell viability was measured 24-h after exposure stroke like conditions in vitro. In supplemented diet mice, we report improved motor function after ischemic damage compared to mice fed a control diet after ischemic damage. Within the perilesional cortex, we show enhanced proliferation, neuroplasticity and anti-oxidant activity in mice fed the supplemented diet. A genetic MTHFR deficiency resulted in neurodegeneration after exposure to in vitro models of stroke, by activating apoptosis promoting p53-dependent mechanisms. These results suggest that one-carbon metabolism plays a significant role in recovery after stroke and MTHFR deficiency contributes to poor recovery from stroke.


Assuntos
Colina/administração & dosagem , Suplementos Nutricionais , Plasticidade Neuronal/efeitos dos fármacos , Recuperação de Função Fisiológica/efeitos dos fármacos , Acidente Vascular Cerebral/dietoterapia , Complexo Vitamínico B/administração & dosagem , Animais , Masculino , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Camundongos , Camundongos Endogâmicos C57BL , Plasticidade Neuronal/fisiologia , Distribuição Aleatória , Recuperação de Função Fisiológica/fisiologia , Acidente Vascular Cerebral/metabolismo , Acidente Vascular Cerebral/patologia
12.
Mol Cell Neurosci ; 74: 25-33, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26995507

RESUMO

Tissue plasminogen activator (tPA) is a thrombolytic agent commonly used in the treatment of ischemic stroke. While the thrombolytic effects of tPA have been well established, the impact of this blood-brain barrier (BBB) crossing drug on neurons is not known. Given the widespread use of tPA in the clinical setting and the strict therapeutic window established for effective use of the drug, we examined the molecular mechanisms mediating the impact of tPA on postnatal cortical neurons isolated from the mouse brain. Dissociated postnatal primary cortical neurons were treated with tPA and the effects on neuron survival were evaluated. Pharmacological inhibitors of several signaling pathways previously implicated in neuroprotection (mTOR, JAK/STAT, MAPK and PKA-dependent mechanisms) were used to pinpoint the mechanistic effectors of tPA on neuron survival in vitro. We report here that tPA treatment results in a time-dependent neuroprotective effect on postnatal cortical neurons that relies predominantly on Janus kinase (JAK) and mammalian target of rapamycin (mTOR) signaling mechanisms. Taken together, these data suggest that tPA promotes neuroprotection in a temporally-regulated manner and that both JAK and mTOR signaling effectors are critical mediators of this neuroprotective effect. The results suggest the possibility of targeting these defined mechanisms to potentially expand the therapeutic window for tPA.


Assuntos
Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Serina-Treonina Quinases TOR/metabolismo , Ativador de Plasminogênio Tecidual/farmacologia , Animais , Sobrevivência Celular , Células Cultivadas , Córtex Cerebral/citologia , Janus Quinases/antagonistas & inibidores , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Transdução de Sinais
13.
Eur J Neurosci ; 43(1): 17-24, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26474338

RESUMO

Clinical stroke usually results from a cerebral ischaemic event, and is frequently a debilitating condition with limited treatment options. A significant proportion of clinical strokes result from specific damage to the subcortical white matter (SWM), but currently there are few animal models available to investigate the pathogenesis and potential therapeutic strategies to promote recovery. Granulocyte macrophage colony-stimulating factor (GM-CSF) is a cytokine that has been previously shown to promote neuroprotective effects after brain damage; however, the mechanisms mediating this effect are not known. Here, it is reported that GM-CSF treatment results in dramatic functional improvement in a white matter model of stroke in mice. SWM stroke was induced in mice by unilateral injections of the vasoconstrictor, endothelin-1 (ET-1). The results reveal that ET-1-induced stroke impairs skilled motor function on the single pellet-reaching task and results in forelimb asymmetry, in adult mice. Treatment with GM-CSF, after stroke, restores motor function and abolishes forelimb asymmetry. The results also indicate that GM-CSF promotes its effects by activating mammalian target of rapamycin signalling mechanisms in the brain following stroke injury. Additionally, a significant increase in GM-CSF receptor expression was found in the ipsilateral hemisphere of the ET-1-injected brain. Taken together, the present study highlights the use of an under-utilized mouse model of stroke (using ET-1) and suggests that GM-CSF treatment can attenuate ET-1-induced functional deficits.


Assuntos
Infarto Encefálico/complicações , Corpo Caloso/efeitos dos fármacos , Corpo Caloso/patologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/administração & dosagem , Atividade Motora/efeitos dos fármacos , Recuperação de Função Fisiológica/efeitos dos fármacos , Substância Branca/efeitos dos fármacos , Substância Branca/patologia , Animais , Infarto Encefálico/induzido quimicamente , Corpo Caloso/lesões , Modelos Animais de Doenças , Endotelina-1 , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Receptores de Fator Estimulador das Colônias de Granulócitos e Macrófagos/metabolismo , Córtex Sensório-Motor/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Substância Branca/lesões
14.
Biochem J ; 461(2): 205-12, 2014 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-24800750

RESUMO

Hyperhomocysteinaemia can contribute to cognitive impairment and brain atrophy. MTRR (methionine synthase reductase) activates methionine synthase, which catalyses homocysteine remethylation to methionine. Severe MTRR deficiency results in homocystinuria with cognitive and motor impairments. An MTRR polymorphism may influence homocysteine levels and reproductive outcomes. The goal of the present study was to determine whether mild hyperhomocysteinaemia affects neurological function in a mouse model with Mtrr deficiency. Mtrr+/+, Mtrr+/gt and Mtrrgt/gt mice (3 months old) were assessed for short-term memory, brain volumes and hippocampal morphology. We also measured DNA methylation, apoptosis, neurogenesis, choline metabolites and expression of ChAT (choline acetyltransferase) and AChE (acetylcholinesterase) in the hippocampus. Mtrrgt/gt mice exhibited short-term memory impairment on two tasks. They had global DNA hypomethylation and decreased choline, betaine and acetylcholine levels. Expression of ChAT and AChE was increased and decreased respectively. At 3 weeks of age, they showed increased neurogenesis. In the cerebellum, mutant mice had DNA hypomethylation, decreased choline and increased expression of ChAT. Our work demonstrates that mild hyperhomocysteinaemia is associated with memory impairment. We propose a mechanism whereby a deficiency in methionine synthesis leads to hypomethylation and compensatory disturbances in choline metabolism in the hippocampus. This disturbance affects the levels of acetylcholine, a critical neurotransmitter in learning and memory.


Assuntos
Cerebelo/metabolismo , Ferredoxina-NADP Redutase/genética , Hipocampo/metabolismo , Homocistinúria/metabolismo , Hiper-Homocisteinemia/metabolismo , Memória de Curto Prazo , Acetilcolinesterase/genética , Acetilcolinesterase/metabolismo , Animais , Apoptose , Betaína/metabolismo , Cerebelo/patologia , Colina/metabolismo , Colina O-Acetiltransferase/genética , Colina O-Acetiltransferase/metabolismo , Metilação de DNA , Modelos Animais de Doenças , Ferredoxina-NADP Redutase/deficiência , Expressão Gênica , Hipocampo/patologia , Homocisteína/metabolismo , Homocistinúria/genética , Homocistinúria/patologia , Hiper-Homocisteinemia/genética , Hiper-Homocisteinemia/patologia , Masculino , Metionina/metabolismo , Camundongos , Camundongos Knockout , Transmissão Sináptica
15.
Front Nutr ; 11: 1285502, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38450239

RESUMO

Elevated plasma homocysteine levels have been identified as a significant, independent risk factor for the development of cognitive decline including Alzheimer's disease. While several studies have explored the link between homocysteine and disease risk, the associations have not been entirely clear. Elevated levels of homocysteine serve as a disease marker and understanding the underlying cause of these increased levels (e.g., dietary or genetic deficiency in one-carbon metabolism, 1C) will provide valuable insights into neurological disease risk and outcomes. Previous cell culture experiments investigating the mechanisms involved used ultra-high levels of homocysteine that are not observed in human patients. These studies have demonstrated the negative impacts of ultra-high levels of homocysteine can have on for example proliferation of neuroprogenitor cells in the adult hippocampus, as well as triggering neuronal apoptosis through a series of events, including DNA damage, PARP activation, NAD depletion, mitochondrial dysfunction, and oxidative stress. The aim of this mini-review article will summarize the literature on deficiencies in 1C and how they contribute to disease risk and outcomes and that homocysteine is a marker of disease.

16.
Neural Regen Res ; 19(8): 1728-1733, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38103238

RESUMO

Traumatic brain injury is a major cause of death and disability worldwide, affecting over 69 million individuals yearly. One-carbon metabolism has been shown to have beneficial effects after brain damage, such as ischemic stroke. However, whether increasing one-carbon metabolite vitamins impacts traumatic brain injury outcomes in patients requires more investigation. The aim of this review is to evaluate how one-carbon metabolites impact outcomes after the onset of traumatic brain injury. PubMed, Web of Science, and Google Scholar databases were searched for studies that examined the impact of B-vitamin supplementation on traumatic brain injury outcomes. The search terms included combinations of the following words: traumatic brain injury, dietary supplementation, one-carbon metabolism, and B-vitamins. The focus of each literature search was basic science data. The year of publication in the literature searches was not limited. Our analysis of the literature has shown that dietary supplementation of B-vitamins has significantly improved the functional and behavioral recovery of animals with traumatic brain injury compared to controls. However, this improvement is dosage-dependent and is contingent upon the onset of supplementation and whether there is a sustained or continuous delivery of vitamin supplementation post-traumatic brain injury. The details of supplementation post-traumatic brain injury need to be further investigated. Overall, we conclude that B-vitamin supplementation improves behavioral outcomes and reduces cognitive impairment post-traumatic brain injury in animal model systems. Further investigation in a clinical setting should be strongly considered in conjunction with current medical treatments for traumatic brain injury-affected individuals.

18.
Nutrients ; 15(18)2023 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-37764675

RESUMO

Aging results in more health challenges, including neurodegeneration. Healthy aging is possible through nutrition as well as other lifestyle changes. One-carbon (1C) metabolism is a key metabolic network that integrates nutritional signals with several processes in the human body. Dietary supplementation of 1C components, such as folic acid, vitamin B12, and choline are reported to have beneficial effects on normal and diseased brain function. The aim of this review is to summarize the current clinical studies investigating dietary supplementation of 1C, specifically folic acid, choline, and vitamin B12, and its effects on healthy aging. Preclinical studies using model systems have been included to discuss supplementation mechanisms of action. This article will also discuss future steps to consider for supplementation. Dietary supplementation of folic acid, vitamin B12, or choline has positive effects on normal and diseased brain function. Considerations for dietary supplementation to promote healthy aging include using precision medicine for individualized plans, avoiding over-supplementation, and combining therapies.


Assuntos
Suplementos Nutricionais , Envelhecimento Saudável , Humanos , Ácido Fólico/farmacologia , Encéfalo , Vitamina B 12/farmacologia , Colina/farmacologia
19.
Nutrients ; 15(7)2023 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-37049396

RESUMO

Maternal dietary levels of one-carbon (1C) metabolites (folic acid and choline) during pregnancy play a vital role in neurodevelopment. However, the impact of maternal dietary deficiencies on offspring stroke outcomes later in life remains undefined. The aim of this study was to investigate the role of maternal dietary deficiencies in folic acid and choline on ischemic stroke outcomes in middle-aged offspring. Female mice were maintained on either a control or deficient diet prior to and during pregnancy and lactation. At 10 months of age ischemic stroke was induced in male and female offspring. Stroke outcome was assessed by measuring motor function and brain tissue. There was no difference in offspring motor function; however, sex differences were present. In brain tissue, maternal dietary deficiency increased ischemic damage volume and offspring from deficient mothers had reduced neurodegeneration and neuroinflammation within the ischemic region. Furthermore, there were changes in plasma 1C metabolites as a result of maternal diet and sex. Our data indicate that maternal dietary deficiencies do not impact offspring behavior after ischemic stroke but do play a role in brain histology and one-carbon metabolite levels in plasma. Additionally, this study demonstrates that the sex of mice plays an important role in stroke outcomes.


Assuntos
AVC Isquêmico , Acidente Vascular Cerebral , Gravidez , Feminino , Masculino , Camundongos , Animais , Ácido Fólico , Colina/farmacologia , Lactação , Inflamação , Suplementos Nutricionais
20.
Neural Regen Res ; 18(11): 2443-2448, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37282475

RESUMO

Maternal one-carbon metabolism plays an important role in early life programming. There is a well-established connection between the fetal environment and the health status of the offspring. However, there is a knowledge gap on how maternal nutrition impacts stroke outcomes in offspring. The aim of our study was to investigate the role of maternal dietary deficiencies in folic acid or choline on stroke outcomes in 3-month-old offspring. Adult female mice were fed a folic acid-deficient diet, choline-deficient diet, or control diet 4 weeks before pregnancy. They were continued on diets during pregnancy and lactation. Male and female offspring were weaned onto a control diet and at 2 months of age were subjected to ischemic stroke within the sensorimotor cortex via photothrombotic damage. Mothers maintained on either a folic acid-deficient diet or choline-deficient diet had reduced levels of S-adenosylmethionine in the liver and S-adenosylhomocysteine in the plasma. After ischemic stroke, motor function was impaired in 3-month-old offspring from mothers receiving either a folic acid-deficient diet or choline-deficient diet compared to the animals receiving a control diet. In brain tissue, there was no difference in ischemic damage volume. When protein levels were assessed in ischemic brain tissue, there were lower levels of active caspase-3 and hypoxia-inducible factor 1α in males compared to females and betaine levels were reduced in offspring from the mothers receiving a choline-deficient diet. Our results demonstrate that a deficient maternal diet at critical time points in neurodevelopment results in worse stroke outcomes. This study emphasizes the importance of maternal diet and the impact it can have on offspring health.

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